I have a 100,000 litre free form In ground pool built in 1964. It's shot dyed gunnite and in good condition. At sometime in the past all the underground pipes were re routed from one pump house to another and they all have a street elbow connecting old and new pipes. The connection is made with barbed abs or pvc fittings held in place with stainless steel hose clamps. Last week one of the elbows cracked and water saturated the lawn, eventually bubbling up in a sodden mess. I excavated and about 3 feet down found seven pipes (and 2 electrical conduits) as described above. The cracked fitting was for the spa supply. It's been repaired and now it's time to backfill. All of which leads to my question- the fittings are all the same age, but I don't feel up to replacing them all right now. They are all in good shape and there is no evidence of fatigue. But it was a brutal job excavating the pipes through heavy, dense compacted clay. I ended up with a pressure washer and shop vac making like a vacuum excavator. I would love advice about possible alternatives to backfilling with soil. I wondered about covering the pipes with gravel then landscape cloth with a few inches of top soil to finish so that I could uncover the pipes quickly if I needed to. But I am worried that they will be subject to freezing in the cold Ontario winters. I know they are all blown out at closing but the pipes are old and I think that the spa supply crack might have been caused by water leaking in over the winter. Any advice is much appreciated.